Immune monitoring assays for patient stratification and treatment efficacy in clinical trials are in demand. We have recently described a cost-effective non-invasive assay to determine the immune status of glioblastoma patients. Profiling antitumor serum antibodies by customized printed peptide arrays identified response against a tenascin-C (TNC) peptide as a robust prognostic biomarker.
Autoantibodies specific to estrogen receptor alpha act as estrogen agonists and their levels correlate with breast cancer cell proliferation
Estrogen receptors have recently been demonstrated at the cell surface. Unlike nuclear receptors, they are able to trigger rapid responses inside the cells. In this study, we evaluated the presence and the possible role of autoantibodies specific to estrogen receptor (anti-ER Abs) in the peripheral blood of breast cancer patients. Anti-ERα Abs were detectable in 22/48 (46%) patients’ sera and their levels positively correlated with the percentage of Ki-67-positive breast cancer cells. Anti-ERα Abs purified from breast cancer patients’ sera were able: (i) to recognize ERα epitopes expressed at the cell surface of ER-positive breast cancer cells, (ii) to trigger rapid extracellular signal-regulated kinase (ERK) phosphorylation, and (iii) to induce cell proliferation. Our results suggest that anti-ERα Abs can act as estrogen agonists playing a pathogenetic role as breast cancer-promoting factors. These autoantibodies could also be considered as possible peripheral blood biomarkers indicative of the breast cancer growth potential.
Combinatorial Synthesis of Peptide Arrays onto a Microchip
Beyer, M.; Nesterov, A.; Block, I.; Konig, K.; Felgenhauer, T.; Fernandez, S.; Leibe, K.; Torralba, G.; Hausmann, M.; Trunk, U.; Lindenstruth, V.; Bischoff, F. R.; Stadler, V.; Breitling, F.
Arrays promise to advance biology through parallel screening for binding partners. We show the combinatorial in situ synthesis of 40,000 peptide spots per square centimeter on a microchip. Our variant Merrifield synthesis immobilizes activated amino acids as monomers within particles, which are successively attracted by electric fields generated on each pixel electrode of the chip. With all different amino acids addressed, particles are melted at once to initiate coupling. Repetitive coupling cycles should allow for the translation of whole proteomes into arrays of overlapping peptides that could be used for proteome research and antibody profiling.
Multifunctional CMOS Microchip Coatings for Protein and Peptide Arrays
Stadler, Volker; Beyer, Mario; König, Kai; Nesterov, Alexander; Torralba, Gloria; Lindenstruth, Volker; Hausmann, Michael; Bischoff, F. Ralf; Breitling, Frank
Complementary metal oxide semiconductor (CMOS) microelectronic chips fulfill important functions in the field of biomedical research, ranging from the generation of high complexity DNA and protein arrays to the detection of specific interactions thereupon. Nevertheless, the issue of merging pure CMOS technology with a chemically stable surface modification which further resists interfering nonspecific protein adsorption has not been addressed yet. We present a novel surface coating for CMOS microchips based on poly(ethylene glycol)methacrylate graft polymer films, which in addition provides high loadings of functional groups for the linkage of probe molecules. The coated microchips were compatible with the harshest conditions emerging in microarray generating methods, thoroughly retaining structural integrity and microelectronic functionality. Nonspecific adsorption of proteins on the chip’s surface was completely obviated even with complex serum protein mixtures. We could demonstrate the background-free antibody staining of immobilized probe molecules without using any blocking agents, encouraging further integration of CMOS technology in proteome research.
